New unrest has been noticed around 3 volcanoes, ongoing activity was reported for 9 volcanoes. This report covers active volcanoes in the world recorded from October 17 – October 23, 2012 based on Smithsonian/USGS criteria.
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program. Updated by 23:00 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth’s volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the “Criteria and Disclaimers” section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
New activity/unrest: | Alaid, Kuril Islands (Russia) | Kliuchevskoi, Central Kamchatka (Russia) | Raung, Eastern Java (Indonesia)
Ongoing activity: | Fuego, Guatemala | Galeras, Colombia | Karymsky, Eastern Kamchatka (Russia) |Kilauea, Hawaii (USA) | Little Sitkin, Aleutian Islands | Pagan, Mariana Islands | Popocatépetl, México |Sakura-jima, Kyushu | Shiveluch, Central Kamchatka (Russia)
ALAID, Kuril Islands (Russia)
50.858°N, 155.55°E; summit elev. 2339 m
According to KVERT, observers on Paramushir Island (SE) reported weak gas-and-steam activity from Alaid during 11 and 16-17 October. A thermal anomaly on the volcano was detected in satellite imagery during 12 and 14-17 October. Cloud cover prevented observations during 19-22 October. Observers on Shumshu Island (50 km E) reported that an ash plume rose 700 m above the crater on 23 October and a thermal anomaly was detected in satellite imagery. The Aviation Color Code remained at Yellow.
Geologic summary: The highest and northernmost volcano of the Kurile Islands, 2,339-m-high Alaid is a symmetrical stratovolcano when viewed from the N, but has a 1.5-km-wide summit crater that is breached widely to the S. Alaid is the northernmost of a chain of volcanoes constructed W of the main Kuril archipelago and rises 3,000 m from the floor of the Sea of Okhotsk. Numerous pyroclastic cones dot the lower flanks of Alaid, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption. Strong explosive eruptions have occurred from the summit crater beginning in the 18th century. Reports of eruptions in 1770, 1789, 1821, 1829, 1843, 1848, and 1858 were considered incorrect by Gorshkov (1970). Explosive eruptions in 1790 and 1981 were among the largest in the Kurile Islands.
KLIUCHEVSKOI, Central Kamchatka (Russia)
56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported moderate seismic activity at Kliuchevskoi during 12-19 October. Strombolian activity was observed during 13-15 October; clouds prevented views on the other days. A weak thermal anomaly was detected in satellite imagery during 14-15 October. The Aviation Color Code remained at Yellow.
Geologic summary: Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation, have occurred during the past 3,000 years. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive events from flank craters.
RAUNG, Eastern Java (Indonesia)
8.125°S, 114.042°E; summit elev. 3332 m
Seismicity at Raung increased on 17 October and remained elevated, prompting CVGHM to raise the Alert Level to 2 (on a scale of 1-4) on 18 October. During 18-22 October white plumes rose 50-75 m above the crater. Seismic activity increased significantly on 22 October. That same day the Alert Level was raised to 3. Visitors and residents were warned not to approach the crater within a 3-km radius.
Geologic summary: Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The 3,332-m-high, unvegetated summit of Gunung Raung is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km from the volcano, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively.
14.473°N, 90.880°W; summit elev. 3763 m
INSIVUMEH reported that during 17-19 and 21-23 October white fumarolic plumes from Fuego drifted S and SW. Explosions produced ash plumes that rose 240-640 m above the lava dome and drifted 7 km SW, W, and NW. A lava flow traveled 400-800 m down the Ceniza drainage, producing incandescent block avalanches that reached vegetated areas.
Geologic summary: Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3,763-m-high Fuego and its twin volcano to the N, Acatenango. Construction of Meseta volcano continued until the late Pleistocene or early Holocene, after which growth of the modern Fuego volcano continued the southward migration of volcanism that began at Acatenango. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
1.22°N, 77.37°W; summit elev. 4276 m
INGEOMINAS reported that during 17-23 October cameras around Galeras recorded daily emissions. On 19 and 21 October the plumes contained ash and rose 1.8 km above the crater. On 19 October observatory staff reported fine ashfall on the NE flank and a sulfur odor was reported in Consacá Sandoná (W flank). Staff at the Galeras National Park Wildlife Sanctuary reported sulfur odors on the E side of the volcano. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").
Geologic summary: Galeras, a stratovolcano with a large breached caldera located immediately W of the city of Pasto, is one of Colombia's most frequently active volcanoes. The dominantly andesitic Galeras volcanic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene. Long term extensive hydrothermal alteration has affected the volcano. This has contributed to large-scale edifice collapse that has occurred on at least three occasions, producing debris avalanches that swept to the W and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid Holocene have produced widespread tephra deposits and pyroclastic flows that swept all but the southern flanks. A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.
KARYMSKY, Eastern Kamchatka (Russia)
54.05°N, 159.45°E; summit elev. 1536 m
KVERT reported moderate seismic activity from Karymsky during 12-19 October. Seismic data indicated that ash plumes possibly rose to an altitude of 6 km (19,700 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 14 October, and an ash plume drifted 64 km N the next day. The Aviation Color Code remained at Orange.
Geologic summary:Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.
KILAUEA, Hawaii (USA)
19.421°N, 155.287°W; summit elev. 1222 m
During 17-23 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. Cracking noises, audible from the Jaggar overlook and caused by rocks of the vent wall fracturing from the heat, emanated sporadically from the vent. On 18 October the lake rose to a level 42 m below Halema'uma'u Crater floor, and the next day the lake rose to 38 m below the floor. During 21-23 October the lake rose to within 33 m of the crater floor. Small collapses of rock into the N portion of the lava lake triggered small spatter explosions on 21 and 23 October.
Lava flows accumulated at the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.4 km from the coast. Flows also remained active on the pali. At Pu'u 'O'o Crater, incandescence was visible from lava flows in the S pit, lava circulating in the NE pit, and from the W edge of the crusted N pit. Three small lava flows erupted from a spatter cone on the S side of the crater floor on 17 October. Two fuming hot vents in the same area were observed the next day. Activity at Pu'u 'O'o Crater was elevated during18-21 October; the lava lake in the NE pit overflowed its rim, the S pit produced three lava flows, and the spatter cone vigorously spattered.
Geologic summary: Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 sq km, destroying nearly 200 houses and adding new coastline to the island.
LITTLE SITKIN, Aleutian Islands
51.95°N, 178.543°E; summit elev. 1174 m
AVO reported that during 17-23 October seismic activity at Little Sitkin remained elevated and satellite views were mostly obscured by clouds. AVO noted that there were no other reports of unusual activity. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Geologic summary: Diamond-shaped Little Sitkin Island is bounded by steep cliffs on the east, north, and NE sides. Little Sitkin volcano contains two nested calderas. The older, nearly circular Pleistocene caldera is 4.8 km wide, may have once contained a caldera lake, and was partially filled by a younger cone formed mostly of andesitic and dacitic lava flows. The elliptical younger caldera is 2.7 x 4 km wide; it lies within the eastern part of the older caldera and shares its eastern and southern rim. The younger caldera partially destroyed the lava cone within the first caldera and is of possible early Holocene age. Young-looking dacitic lava flows, erupted in 1828 (Kay, in Wood and Kienle 1990), issued from the central cone within the younger caldera and from a vent on the west flank outside the older caldera. Fumarolic areas are found near the western coast, along the NW margin of the older caldera, and from the summit crater down the southern flank for a 1 km distance.
PAGAN, Mariana Islands
18.13°N, 145.80°E; summit elev. 570 m
Continuous steam-and-gas plumes from Pagan were observed in clear satellite images during 12-19 October. According to NASA's Earth Observatory, a satellite image acquired on 16 October showed a steam-and-gas plume drifting WNW. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Geologic summary: Pagan Island, the largest and one of the most active of the Mariana Islands volcanoes, consists of two stratovolcanoes connected by a narrow isthmus. Both North and South Pagan stratovolcanoes were constructed within calderas, 7 and 4 km in diameter, respectively. The 570-m-high Mount Pagan at the NE end of the island rises above the flat floor of the caldera, which probably formed during the early Holocene. South Pagan is a 548-m-high stratovolcano with an elongated summit containing four distinct craters. Almost all of the historical eruptions of Pagan, which date back to the 17th century, have originated from North Pagan volcano. The largest eruption of Pagan during historical time took place in 1981 and prompted the evacuation of the sparsely populated island.
19.023°N, 98.622°W; summit elev. 5426 m
CENAPRED reported that during 15-23 October seismicity at Popocatépetl indicated continuing gas-and-steam emissions that occasionally contained variable amounts of ash; the plumes rose 0.5-1 km and drifted NW, W, and SW. Incandescence from the crater was observed at night. During 15-16 and 20 October incandescent tephra was ejected 1 km above the crater and fell back in the crater or on the flanks. On 20 October ashfall was reported in Tetela del Volcan (20 km SW). The Alert Level remained at Yellow, Phase Two.
Geologic summary: Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is North America's second-highest volcano. Frequent historical eruptions have been recorded since the beginning of the Spanish colonial era. A small eruption on 21 December 1994 ended five decades of quiescence. Since 1996 small lava domes have incrementally been constructed within the summit crater and destroyed by explosive eruptions. Intermittent small-to-moderate gas-and-ash eruptions have continued, occasionally producing ashfall in neighboring towns and villages.
31.585°N, 130.657°E; summit elev. 1117 m
JMA reported that explosions from Sakura-jima's Showa Crater during 15-19 October explosions ejected tephra as far as 1,300 m from the crater. Based on information from JMA, the Tokyo VAAC reported that explosions during 17-21 October produced plumes that rose to altitudes of 1.8-3.7 km (6,000-12,000 ft) a.s.l. and drifted NE, E, and S. During 21-23 October pilots observed ash plumes that rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and drifted N and SE.
Geologic summary: Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.
SHIVELUCH, Central Kamchatka (Russia)
56.653°N, 161.360°E; summit elev. 3283 m
Based on visual observations and analyses of satellite data, KVERT reported that during 12-19 October a viscous lava flow continued to effuse on the NW flank of Shiveluch's lava dome, accompanied by hot avalanches and fumarolic activity. Satellite imagery showed a thermal anomaly on the lava dome during 12-16 October; clouds prevented views on the other days. The Aviation Color Code remained at Orange.
Geologic summary: The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.
Source: Global Volcanism Program
Featured image: View of the lava lake at Kīlauea’s summit at sunset. October 18, 2012 — Kīlauea. Credit: USGS.